采用氢化物发生-原子荧光光谱法测定枸杞中砷的含量。样品经硝酸-过氧化氢混合溶液消解,在盐酸(5+95)溶液中,加入20.0 g·L-1硼氢化钾溶液使与溶液中砷(Ⅲ)离子反应生成氢化物。分析中采用载气及屏蔽气的流量依次为400 mL·min-1及1 000 mL·min-1。试样溶液中加入硫脲-抗坏血酸混合溶液作为预还原剂。砷的质量浓度在0.05~10 μg·L-1范围内与荧光强度呈线性关系,方法的检出限(3S/N)为0.032 μg·L-1。应用此法对菠菜标准物质(GBW 10015)进行分析,测定结果与认定值相符合。

HG-AFS was applied to the determinations of arsenic in Lycium chinense. Sample was dissolved with HNO3 and H2O2, and hydride of As(Ⅲ) was generated from HCl(5+95) solution by reacting with 20.0 g·L-1 KBH4 solution. Flow-rates of 400 mL·min-1 for carrier gas and 1 000 mL·min-1 for shielding gas were taken in the analysis. Mixed solution of thiourea and ascorbic acid was added to the sample solution as pre-reductant. Linear relationship between the fluorescence intensity and mass concentration of As found was in the range of 0.05-10 μg·L-1, with detection limit (3S/N) of 0.032 μg·L-1. The proposed method was applied to the analysis of a CRM of spinach (GBW 10015), giving results in consistency with the certified values.